Note
	The following description provides you with general information about the operation of the ibaBM-DP device in redundancy mode. You will find detailed information about differences and special features in comparison to operation on the normal PROFIBUS. For understanding the following description, we suppose that you have basic knowledge in using the ibaBM-DP device.

The redundancy mode of ibaBM-DP and ibaPDA is required if you want to capture data of redundant PROFIBUS systems of a SIMATIC S7-400H control.

Basically, data can also be captured without redundancy mode. The disadvantage is that data have to be captured on each of the both PROFIBUS systems. When analyzing data, the user has to decide which of the two data sets is valid.

In redundancy mode, ibaBM-DP decides automatically and dynamically, which PROFIBUS system sends the valid data sets. Only valid data is sent to ibaPDA for recording.

ibaBM-DP recognizes situations like the switching of a S7-400H CPU to STOP, the failure of a slave connection (e. g. IM153-2 for a redundant ET200) or a broken cable. It then changes dynamically the bus system used for data capturing.

In case, valid data is recognized on both bus systems, the bus system 0 (connected to the X40 plug) is preferred.

In redundancy mode, "sniffing" an existing master/slave communication can be done. You can also use active slaves in ibaBM-DP for sending internal data of the PLC directly to ibaPDA. The active slaves can also have an input data range. Then the signals can be passed from ibaPDA via ibaBM-DP to the master.

Caution
	When using active slaves on ibaBM-DP, you have to take measures in the S7-400H CPU program for preventing an eventual downtime of an active slave (e. g. over OB85) for there will be no negative consequences for the rest of the program.

Note
	Due to the system, for some cycles zero values or „frozen“ values might be recorded when changing the active bus system (e. g. a S7-400H CPU switches to STOP status).

For using redundancy mode, you need an additional license. For detailed information on the order data see chapter Order data. The license can be activated as follows:

• Via the administrator functions in the ibaBM-DP web dialog, see chapter Administration

• Via the I/O manager in ibaPDA in the Profibus browser dialog, see chapter PROFIBUS browser

After having activated the license in the web dialog, the Info page shows that redundancy mode is available.

Note
	ibaBM-DP can either be operated in normal mode or in redundancy mode. A combination of these modes is not possible.